My new game is trying to insert diminished chords wherever I can under a melody. Level one of the game was A-melody to Fly Me to the Moon like so (chords in bold are original harmony, chords in parentheses are passing):
I got some ideas from a chord-melody arrangement I downloaded years ago from Guitar College, but quickly found myself improvising my own harmony, which is of course exactly what should happen. The use of diminished chords comes from an video-lesson with Joe Beck called “Jazz Chord Workout.” He demonstrates how to harmonize a harmonic minor scale using this approach, which was a paradigm shift for me since the only approach I knew was diatonic. Jim Hall also demonstrates an approach to harmonizing a mixolydian scale using dominant chords in a video I saw, so I guessed that all of the diminished chords used here would be enharmonic to the dominant b9 of the chord that follows it: Ab diminished=E7b9, E diminished=A7b9, A dim.=D7b9 F# dim.=B7b9. Looking at the roots of these chords, it’s immediately obvious that they are a fourth apart, just like the original harmony.